How often?
What size?
From where?
Do the missiles launch on failure to serve an image?
How much are you willing to spend?
When do you need it?
For how long?
Obviously, I am assuming it's an engineering problem.
Glacier certainly will be slower, though.
You also may have requirements w.r.t. access time, may want a search facility, may want the ability to serve multiple image sizes, may have legal requirements such as the GDPR, copyrights that differ across the world, etc.